Retopo and Polygon tool not working after some time

I use retopo tool to get my starting polygon then I use the mirror tool to get symmetry, using the mirror tool my polygon are not welded to each other so I use the ctrl+q to get symmetry, now I am using the normal modelling tools not retopo tool to retopo the object, here is the problem when I am editing the mesh that was created with this method retopo tool and polygon tool do not produce anything/not working but when I deselect everything and use the retopo tool it works. Thank you for reading and I hope you fix this soon thanks.

Can you create steps that can reproduce the problem?

Use retopo(character's arm) -->> Create 1 face -->> Mirror -->> Ctrl+q -->> delete the non symmetric polygon.

What do you use the Mirror tool for? I suspect that you created a new mesh after using this tool.

Can you just use 'Use retopo(character's arm) -->> Create 1 face -->> Ctrl+q -->> delete the non symmetric polygon.' without using the Mirror tool?